There are several issues with the security policy:
* The security policy is created with `AFSSLPinningModeNone` which means that even if pinned certificates are set (if config.sslCaCert is not nil), they will be ignored. Pinning will not work at all with this security policy.
* The configuration wrapper for the security policy is a bad idea.
* `verifySSL` controls both invalid certificates and domain validation. A vanilla `AFSecurityPolicy` clearly exposes both `allowInvalidCertificates` and `validatesDomainName`.
* `sslCaCert` only allows for a single pinned certificate. A vanilla `AFSecurityPolicy` clearly exposes a set of pinned certificates and makes it very convenient to load them with either `+[AFSecurityPolicy policyWithPinningMode:]` or `+[AFSecurityPolicy certificatesInBundle:]`
Since the security policy does not work at all and adds confusion, it is better to just remove it and let the user configure a security policy that fits their needs.
* change api and ApiClient to return cancellable NSURLSessionTasks instead of NSNumber
* define a configuration protocol for custom configurations, which can be passed to api clients instead of a global configuration, provide a default implementation with a singleton option
* integrate a workaround for a current JSONModel concurrency bug
* update to new ISO8601 pod
* add missing call to super
* integrate new templates into codegen
* updates documentation templates
* updates petstore objc generated code
* fixes objc client tests
